Cylinder-drum mechanism for cutting machines



Dec. 9, 1924- 1,5l8,213

P. s. MITTS CYLINDER DRUM MECHANISM FOR CUTTING MACHINES Filed March 19,1923 INVENTOR ATTbRNEY Patented Dec. 9, 1924.

UNITED STATES I 1,518,213 PATENT QFFICE.

PHILIP S. MI'ITS, OF SAGINAW, MICHIGAN, ASSIGNOR 'IO MITTS & MERRILL, 0FSAGL NAW, MICHIGAN, A CORPORATION GE MICHIGAN.

CYLINDER-DRUM MECHANISM FOR CUTTING MACHINES.

Application filed March 19, 1923. Serial No. 626,143.

in 'the art towhichit appertains to make anduse the same.

This invention relates to cutting shredders and similar machines andpertains more -'particularly to an improved drum construction 1 for thatclass of cutting shredders knownin the trade as sawmill hogs andemploying a'cylindrical drum having cutting knives on its surface.

This type of machine is adapted for grinding sawmill refuse and also fordisintegrating other materials, for example, waste sheets of veneer andother wood refuse, such as the cores of veneer logs.

Grinding or disintegrating sheet veneer and such materials requires highspeed drums of considerable length. The length for some purposes is asmuch as four feet" being approximately the width of some of thematerialfed to the machine.

The greatly increased length of drum required by sheet veneer and otherWide materials has developed new problems in drum construction and themeans formerly employed for securing the knives to the shorter drums isno longer adequate when employed on long drums, as will be explained.

Insomuch as this veneer shredding machine requiring a long drum is alsoadapted for shredding sawmill refuse, veneer log cores and the like andsince these materials are "veryhard to cut, it has become necessary toanchor the cutting knives so firmly to the elongated drums "abovereferred to as to make it impossible for the knives to shift theirposition onthe drumunder the impact of anybelow to which they may besubjected in ordinary use."

My improvement includes building up a long drum from a plurality ofindependent short-drum sections so that from a number of such unitsections drums of any required length may be constructed. I provide eachof these unit sections with a plurality of knives somountedthat theknives will be sprung or bent to curved formand will be clamped in thatform against a shaped seat. The clamping of the knife is preferablyaccomplished by means of a bolt tightened from outside the drum. Thespringing or bowing of the knife when so clamped effectually preventsthe knife slipping when subjected to unusually hard service. In mypresent application I shall describe and claim means for applying theknifeclamping device to an improved construction. namely, a drumcomprising unit sections of narrow width, adapted to be built up into adrum of any desired length, the sectionsso constructed that the knivescan be sprung and clamped from outside the'periphery of the assembleddrum.

The advantages of such construction both from an operating andproduction standpoint are apparent when it is observed that a set of,say, six knives is usually employed on each drum section, equally spacedaround its periphery. The section, therefore, must be extremely strongand rigid to withstand the strains brought upon it by the siX kniveswhen in action on hard and large materials. I. therefore, provide eachsection with a radial web or with spokes. Such webs or spokesnecessarily prevent access to the interior of a drum built up of severalsections. If it were attempted to make a similar multiwebbed drum in asingle casting, the presence of the webs would make it impracticable toproperly machine the necessary curved faces of the knife seats on thedrum; but by employing a plurality of identical and interchangeableshort unit drum sections, their curved knife-seats may be easily andaccurately machined or otherwise shaped to properly spring and how theknife and to permit the knife to be tightened from outside the drum aspreviously mentioned;

Vith the foregoing and certain other objects in view which will appearlater in the specification, my invention comprises the devices describedand claimed and the equivalents thereof.

In the drawings, Fig. 1 is a part sectional side view, broken away,showing a unit section of a shredding machine drum embodying one form ofmy improvement and ineluding a concave knife seat.

Fig. 2 is a part sectional edge view of the same-with the knife andits'clamping devices removed.

Fig. 3 is a horizontal section on line 3-3 necessary to reach into thecylinder to of F ig. 1, viewed in the direction of the arrows.

Fig. 4 is a fragmetnary sectional view of a modified form of knife seatof the kind illustrated in Fig. 1, the knife removed.

Fig. 5 is a part sectional detail showing a convex knife seat. 1

Fig. 6 is a similar view of a modified form of knife seat such as isillustrated in Fig. 5. As is clearly shown in the drawings, theinvention consists in providing a unit drum section 1 having" the usualhub 2, web 3 and rim 4. The rim is formed with a plurality of internalprojections or lugs 5 with adjacent knife-reeeiving openings or pockets6 through which the cutting knives are inserted as shown in Figs. 4 and5. when in place is clamped against the inner face of the lug 5, beingthe lower face as shown in Figs. 1, 5 and 6. In the periphery of thedrum opposite the clamping face of the lug 5 is formed a bolt-receivingpocket 8 into which a clamping bolt 9 is inserted. The head 10 of bolt9. or, if desired the nut instead of the head of the bolt, is rotatable,

pocket 8 being large enough to receive a socket wrench or other tool forthe purpose. Beneath the knife 7 1s a clamplnsr plate 11 i or itsequivalent preferably threaded to the bolt 9 and adapted to clamp knife7 rigidly against the clamping face of lug 5 when bolt 9 is tightened.

As already explained, the knife is held against shifting when subjectedto unusual impacts, not only by being clamped to the face of lug 5, butalso by being forcibly bowed or sprung in the act of clamping.

The knife may be sprung to concave form on its upper face, as shown in1, or it may be sprungto convex form on its upper face as shown in Figs.5 and 6 and this springing or bowing of the knife may be accomplishedeither by drawing the clamping plate 11, or its equivalent, upward bybolt 9 so that the knife is forced against the concave face of lug 5 asshown in Fig. 1, or it may be similarly clamped by bowing the knifeagainst a face formed as in Fig. 4, where the lower face of the lung iscored or recessed as at 12 Similarly the knife may be bowed intodownwardly concave form as shown in Fig. 5 by being clamped against thedownwardly convex face of lup; or it may be bowed by providing the plate11 with a concave upper surface. as shown in Fig. 6 and clamping thelmife against the lower face of lug 5, which in that case may be formedwith a central projection 18.

In all ofthese forms, however. it will be noted that each unit section 1has its knives 7 so mounted that those knives are sprung and clamped inplace against the lower face of lug 5 by means of bolt 9, which is tightened from outside the cylinder, so it is not The knife tighten theclamping bolt as heretofore.

In long: cylinders, that is, cylinders made up of several unit sections1, it is not possible to reach the clamping bolts of the sertions towardthe middle of the length of such cylinder on account of the webs 3. Thepresent improvement provides bot-h for inserting the knife into eachunit section from outside after the drum is assembled and for tighteningthe bolt 9 by means of its head or nut 10 from a position outside thecylinder.

Furthermore in each instance the knife is not only clamped, but curvedor bowed either convex or concave upwardly. thereby insuring extremlyrigid clamping.

To prevent the knife slipping back and dropping into the cylinder whenthe knife is unclamped I prefer to form a projection 12 on the drum andin the rear of the knife, as shown in Fig. 1.

By the means above described I have produced a unit section forshredding machines that adapts itself readily to building up of longcylinders in which the knives are readily insertible and rigidly clampedfrom outside by being; curved or bent in the act of clamping.

Having; thus described my invention, what I claim and desire to secureby Letters Putent is:

1. A short cylindrical section for builtup multiple section cuttingdrums of the class described, said section formed with a knife-rcceivingopening in its periphery, a lug, integral with said section. a face ofsaid lug; formed to provide a slightly curved knife-receiving seat,extending from the pcriphery of the drum inwardly. and means adapted toforcibly spring said knife into contact with said seat.

2. A short cylindrical section for built-up multiple section cuttingdrums of the class described, having a central web and a rim, saidsection formed with a knife-receiving opening in its periphery, a lugintegral with said rim, a face of said lug formed to provide a slightlycurved knife-receiving; seat extending from the periphery of the druminwardly, a recess in said rim, a bolt in said recess extending throughsaid curved seat, and a knife-clamping plate secured to said bolt andadapted to forcibly spring said knife into contact with said seat.

3. In combination, a short cylindrical section for built-up cuttingdrums, a knifeclamping device comprising a knife-rcceiw ing pocket inthe periphery of said section, a wall of said pocket curved, a. clampingplate having a curved face, a shredding: knife re ceived between thecurved wall of said pocket and the curved face of said clamping plate, abolt socket formed in the exterior periphery of said drum, a bolt insaidsocket,

an end of said bolt engaging said clamping plate, said bolt adapted whentightened from Within said socket to bend and clamp said knife, and aprojection on said drum in the rear of said knife, for the purposes setforth.

4. A short cylindrical section for builtup cutting drums, said sectionformed with a lmife-receiving opening arranged across 10 the peripheryof each section, a lug integral with said section, a face of said lugformed to provide a slightly curved knife-receiving seat extendinginwardly from the periphery of the drum, said seat shaped and adapted tocause said knife to bow or spring when forcibly clamped against saidface, and means for clamping said knife.

In testimony whereof, I affix my signature.

PHILIP S. MITTS.

